Hong Kong's Mandatory Provident Fund system : a study of the evolution of governance and policy tools

published_or_final_versionPolitics and Public AdministrationMasterMaster of Public Administratio

The Sella Turcica dimensions in 12-year-old Southern Chinese: a cross-sectional study

The objective of the study was to measure the dimensions of the sella turcica in southern Chinese population. This retrospective study measured dimensions of sella turcica from lateral cephalometric radiographs obtained from the University of Hong Kong research database with a total of 582 (277 females and 305 males) 12-year-old southern Chinese children, who were randomly selected from schools in Hong Kong. Measurements were made using ImageJ (V1.45s) software for Windows with Frankfurt plane as the horizontal reference direction. Dimensions between genders were compared using Student’s t-tests. The current study found the antero-posterior length and width were 9.13 mm (SD 2.05) and 9.76 mm (SD 1.54), respectively. The sella was highest posteriorly (7.97 mm; SD 1.75 mm) and shortest anteriorly (7.56 mm; SD 1.42). Sella height anterior, sella height median and sella area were greater (p<0.05) in females by 0.53 mm, 0.24 mm and 3.48 mm2, respectively. In conclusion, this study provides the reference parameters for the dimensions of sella turcica for the Southern Chinese population

Probabilistic forecasting of wind power generation using extreme learning machine.

Accurate and reliable forecast of wind power is essential to power system operation and control. However, due to the nonstationarity of wind power series, traditional point forecasting can hardly be accurate, leading to increased uncertainties and risks for system operation. This paper proposes an extreme learning machine (ELM)-based probabilistic forecasting method for wind power generation. To account for the uncertainties in the forecasting results, several bootstrap methods have been compared for modeling the regression uncertainty, based on which the pairs bootstrap method is identified with the best performance. Consequently, a new method for prediction intervals formulation based on the ELM and the pairs bootstrap is developed. Wind power forecasting has been conducted in different seasons using the proposed approach with the historical wind power time series as the inputs alone. The results demonstrate that the proposed method is effective for probabilistic forecasting of wind power generation with a high potential for practical applications in power systems

Optimal prediction intervals of wind power generation

Accurate and reliable wind power forecasting is essential to power system operation. Given significant uncertainties involved in wind generation, probabilistic interval forecasting provides a unique solution to estimate and quantify the potential impacts and risks facing system operation with wind penetration beforehand. This paper proposes a novel hybrid intelligent algorithm approach to directly formulate optimal prediction intervals of wind power generation based on extreme learning machine and particle swarm optimization. Prediction intervals with associated confidence levels are generated through direct optimization of both the coverage probability and sharpness to ensure the quality. The proposed method does not involve the statistical inference or distribution assumption of forecasting errors needed in most existing methods. Case studies using real wind farm data from Australia have been conducted. Comparing with benchmarks applied, experimental results demonstrate the high efficiency and reliability of the developed approach. It is therefore convinced that the proposed method provides a new generalized framework for probabilistic wind power forecasting with high reliability and flexibility and has a high potential of practical applications in power systems

Compost feedstock characteristics and ratio modelling for organic waste materials co-composting in Malaysia

In Malaysia, large amounts of organic materials, which lead to disposal problems, are generated from agricultural residues especially from palm oil industries. Increasing landfill costs and regulations, which limit many types of waste accepted at landfills, have increased the interest in composting as a component of waste management. The objectives of this study were to characterize compost feedstock properties of common organic waste materials available in Malaysia. Thus, a ratio modelling of matching ingredients for empty fruit bunches (EFBs) co-composting using different organic materials in Malaysia was done. Organic waste materials with a C/N ratio of<30 can be applied as a nitrogen source in EFB co-composting. The outcome of this study suggested that the percentage of EFB ranged between 50% and 60%, which is considered as the ideal mixing ratio in EFB co-composting. Conclusively, EFB can be utilized in composting if appropriate feedstock in term of physical and chemical characteristics is coordinated in the co-composting process

Effect of using agro-fertilizers and N-fixing Azotobacter enhanced biofertilizers on the growth and yield of corn

Corn is an important crop and is grown widely around the world. Corn is a food source for human as well as animal and processed into industrial product such as ethanol. Corn is one of the important productions of Malaysia as the climate is suitable for corn growth. In this study, organic fertilizers such as biofertilizer, N-fixing Azotobacter enhanced biofertilizers and compost were added to the soil to determine best practice in using organic fertilizers for higher corn yield and growth. The study was conducted in plot experiment with five replications based on randomized block design in the summer of 2012. All plots were manually harvested and yield was adjusted to 15% moisture. Grain yield (total corn harvested) at maturity was determined by harvesting the two central rows of each plot. Statistical analysis was performed on the effect of fertilizer treatments on plant growth, corn yield and nitrogen, phosphorous and potassium contents of plant materials. The means were compared according to Duncan multiple range test. The results showed that organic fertilizers in the form of N-fixing Azotobacter enhanced biofertilizer increased yield with positive effects on measured plant height, weight and leaf index. Given the significant enhancement in growth and yield of corn taking place mainly with N-fixing Azotobacter fertilizers under organic condition, the mechanism for this beneficial effect could be due to the more balanced nutrition and improved absorption of nitrogen and other mineral nutrients by the corn

The impact of positron emission tomography on primary tumour delineation and dosimetric outcome in intensity modulated radiotherapy of early T-stage nasopharyngeal carcinoma

Background: In intensity modulated radiotherapy (IMRT) of nasopharyngeal carcinoma (NPC), accurate delineation of the gross tumour volume (GTV) is important. Image registration of CT and MRI has been routinely used in treatment planning. With recent development of positron emission tomography (PET), the aims of this study were to evaluate the impact of PET on GTV delineation and dosimetric outcome in IMRT of early stage NPC patients.Methods: Twenty NPC patients with T1 or T2 disease treated by IMRT were recruited. For each patient, 2 sets of NP GTVs were delineated separately, in which one set was performed using CT and MRI registration only (GTVCM), while the other set was carried out using PET, CT and MRI information (GTVCMP). A 9-field IMRT plan was computed based on the target volumes generated from CT and MRI (PTVCM). To assess the geometric difference between the GTVCM and GTVCMP, GTV volumes and DICE similarity coefficient (DSC), which measured the geometrical similarity between the two GTVs, were recorded. To evaluate the dosimetric impact, the Dmax, Dmin, Dmean and D95 of PTVs were obtained from their dose volume histograms generated by the treatment planning system.Results: The overall mean volume of GTVCMP was greater than GTVCM by 4.4 %, in which GTVCMP was slightly greater in the T1 group but lower in the T2 group. The mean DSC of the whole group was 0.79 ± 0.05. Similar mean DSC values were also obtained from the T1 and T2 groups separately. The dosimetric parameters of PTVCM fulfilled the planning requirements. When applying this plan to the PTVCMP, the average Dmin (56.9 Gy) and D95 (68.6 Gy) of PTVCMP failed to meet the dose requirements and demonstrated significant differences from the PTVCM (p = 0.001 and 0.016 respectively), whereas the doses to GTVCMP did not show significant difference with the GTVCM.Conclusion: In IMRT of early stage NPC, PET was an important imaging modality in radiotherapy planning so as to avoid underdosing the PTV, although its effect on GTV delineation was not significant. It was recommended that PET images should be included in the treatment planning of NPC patients.Department of Health Technology and Informatic

Characterization of keratinocytes, fibroblasts and melanocytes isolated from human skin using gene markers

Cells isolated from skin have wide applications in studies of the pathogenesis of skin-related diseases and the construction of 3D skin equivalents. This study aimed to isolate keratinocytes, fibroblasts, and melanocytes from human foreskin and characterize the purity of the cell types. Keratinocytes, fibroblasts, and melanocytes from human foreskin were isolated by differential trypsinization and media selection. The purity of the cell types was characterized based on the expression of gene markers. The assessment of gene marker expression involved RNA extraction, primer design, quantitative polymerase chain reaction (qPCR) and immunocytochemical staining. Our results showed that in cocultures of keratinocytes and fibroblasts isolated from the dermis, fibroblasts could be separated from keratinocytes by quick trypsinization and culture in Dulbecco’s modified Eagle’s medium. The remaining keratinocytes are cultured in Epilife medium. Melanocytes in cocultures of melanocytes and keratinocytes isolated from the epidermis could be selected by changing Epilife medium to M254 medium. Gene marker results suggested that cytokeratin 14 (CK14) is a suitable marker for keratinocytes, elastin (ELN) is a suitable marker for fibroblasts, and tyrosinase (TYR) and tyrosinase-related proteins 1 and 2 (TYRP1 and TYRP2) are suitable markers for melanocytes. In conclusion, keratinocytes, fibroblasts, and melanocytes can be isolated from the same human foreskin sample by differential trypsinization and media selection techniques and characterized by suitable gene markers. This finding will aid in the isolation of pure skin cell types for various applications in regenerative medicine and toxicity studies

Termite digestomes as a potential source of symbiotic microbiota for lignocelluloses degradation: a review

Termites thrive in great abundance in terrestrial ecosystems and the symbiotic gut microbiota play important roles in digestion of lignocelluloses and nitrogen metabolism. Termites are excellent models of biocatalysts as they inhabit dense microbes in their guts that produce digestive enzymes to decompose lignocelluloses and convert it to end products such as sugars, hydrogen, and acetate. Different of digestive system between lower and higher termites which lower termites dependent on their dual decomposing system, consisting of termite's own cellulases and gut's protists. Higher termites decompose cellulose using their own enzymes, because of the absence of symbiotic protists. Termite gut prokaryotes efficiently support lignocelluloses degradation. In this review, a brief overview of recent experimental works, development and commercialization is discussed. Significant progress has been made to isolate cellulolytic strains from termites and optimise the digestion efficiency of cellulose. Future perspective should emphasize the isolation of cellulolytic strains from termites, genetically modifying or immobilization of the microbes which produce the desired enzyme and thus benefits on the microbiology and biotechnology